I read that the gas is caused from any organic material left om the material that you are tumbling. The composting of this material makes a gas . I am quite a tumbler and have polishing units from very small to huge{100lbs} and never had this problem. With my rubber drums I try to create a negative preasure by pushing the bottom of the drum in and reliecing the air. I also use hot water to start with the idea that as it cools and contracts the chance of expantion is deminished. I find this to work for me.
Just a thought,,, Does this happen when you are on your first stage or ??. Another thought is ,,, the same type of material.

I hope something here helps in your future projects. Mike

From mike blampied - August 23, 2008 at 09:08:03
Email: mblampied[ ]telus.net

Message: 66910